Best way for Biden to win over Bernie supporters?

[Perseus]

8. "they only seem to exist as an online presence" I think that is part of the question

How do stop them from being an online presence only to cast votes for the Democratic candidate?

And the fears are not overblown, there was a lot of abstinence in 2016 from Bernie's supporters that could have made a difference in the key states, we need all the votes we can get, no matter who the nominee is.

The other question is, will Biden supporters come out to vote for Sanders if he were to win the nomination? I hear all talk about Bernie's supporters, but I don't hear anyone asking Biden supporters. I only read a post someone wrote here in DU, a Biden supporter, and he said that "he would never vote for Sanders, no matter what!" The good thing is that many Biden supporters jumped at it explaining the importance of "vote blue no matter who", not sure if they changed his mind, but nonetheless, it is a question that must be asked.